054B/new generation frigate

taxiya said:

You are precisely suggesting a disasterous design like Type-45 IEPS.

You seem to lack basic engineering knowledge. The core of design is to have power granularity which is to have multiple various sized engines combined. NOT a single beast to do all the job from 5% load at the port all the way up to 100% power in a dash. In case of auxilary power, having a single 12MW diesel is worst for a 4000 to 5000 tonne ship, a single 8MW is worse, 2 to 3 4MW is good

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When exactly have I mentioned that I was suggesting to power ships with a single engine? Read my further posts on this subject please.

Tomboy said:

AFAIK, QE class carriers use two 12MW units along with two 8MW units for 40MW combined. Main utility for larger engine IMO would be for gensets for future large surface combatants or if PLAN still decides to stay all diesel for their next generation frigates, larger diesel sets could definitely help there.

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054B uses 4*7.28MW diesels, a larger CODAD next generation frigate could use 4 slightly more powerful sets of equal rating or two larger sets along with two smaller sets precisely for the reasons you are suggesting.

Tomboy said:

When exactly have I mentioned that I was suggesting to power ships with a single engine? Read my further posts on this subject please.

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I didn't suggest what you think I did. Please read my post again. The sentence that you replied to was about auxilary power which is only 30% of the total power.

In case of auxilary power, having a single 12MW diesel is worst for a 4000 to 5000 tonne ship, a single 8MW is worse, 2 to 3 4MW is good

Gloire_bb said:

To be fair, it appears than Chinese goal is to build world's largest navy.
It just didn't get a flowery "two ocean navy announcement", and PLAN is still waiting to finish working on carrier branch.

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It may well be that they happen to end up being the world's largest navy by virtue of meeting its national requirements.

But size is not the explicit endpoint aim itself.

taxiya said:

I didn't suggest what you think I did. Please read my post again. The sentence that you replied to was about auxilary power which is only 30% of the total power.

In case of auxilary power, having a single 12MW diesel is worst for a 4000 to 5000 tonne ship, a single 8MW is worse, 2 to 3 4MW is good

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Isn't that solvable with energy storage systems? You could run the 10MW engine at peak efficiency to charge a power bank, using the storage to handle those 5% 'port loads' without under-loading the engine. Also, an IEPS setup with a set of 4x10MW diesel generators has greater reliability and redundancy than the Type 45 IEPS setup. Though I agree that a 10MW generator as an auxiliary engine is overkill, a setup similar to the Mistral class (swapping one 10MW unit for two smaller engines) would maintain comparable total power while improving load management flexibility.

F=XX Corsair said:

Isn't that solvable with energy storage systems? You could run the 10MW engine at peak efficiency to charge a power bank, using the storage to handle those 5% 'port loads' without under-loading the engine. Also, an IEPS setup with a set of 4x10MW diesel generators has greater reliability and redundancy than the Type 45 IEPS setup. Though I agree that a 10MW generator as an auxiliary engine is overkill, a setup similar to the Mistral class (swapping one 10MW unit for two smaller engines) would maintain comparable total power while improving load management flexibility.

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No, auxilary power is constantly running for certain load level up to 30% of max load of the ship. Energy storage acts as buffer for less than 60 minutes. Auxilary power is still part of the main power supply like power grid on land, while energy storage is like UPS.

The highlighted setup (multiple smaller instead of one larger) is the common design principle used in many naval ships including 054B. These last posts would not have happened if Tomboy did not brought up this "China lacks larger diesel power plant" thing in the first place.

Those 052B(s?) in the satelite photo showing a suspected 071

F=XX Corsair said:

Isn't that solvable with energy storage systems? You could run the 10MW engine at peak efficiency to charge a power bank, using the storage to handle those 5% 'port loads' without under-loading the engine. Also, an IEPS setup with a set of 4x10MW diesel generators has greater reliability and redundancy than the Type 45 IEPS setup. Though I agree that a 10MW generator as an auxiliary engine is overkill, a setup similar to the Mistral class (swapping one 10MW unit for two smaller engines) would maintain comparable total power while improving load management flexibility.

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If we have a future IEPS Type-054B, it's better to have a mix of generator sizes, so you can run an appropriate number of them at the most efficient range. In addition, you would still want at least 4 engines for redundancy purposes.

So they could go for the following: 2*5MW plus 2*12MW (total 34MW)

For non-wartime cruising, they could probably run the 2 smaller diesels efficiently at 75-100% load and still get 17-20knots.

With 5MW diesel engines, I'm not sure whether it is worth implementing an energy storage system. Yes, at low loads, it would be less efficient, but fuel is pretty cheap, and it takes time/money/space to implement an energy storage system.

taxiya said:

No, auxilary power is constantly running for certain load level up to 30% of max load of the ship. Energy storage acts as buffer for less than 60 minutes. Auxilary power is still part of the main power supply like power grid on land, while energy storage is like UPS.

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I think we’re looking at two different scales of storage. I'm thinking of a large capacity ESS (comparable to the 9MWh TENER Stack's level of density) moving beyond simple 'buffering' to fully replacing auxiliary generator sets. At this density, the ESS can sustain auxiliary loads (which at 30% of a typical frigate’s 3/5MW max load, sits around 1–1.7MW) for several hours, only to be recharged by one of the main generators (running at an optimal efficiency) for just over an hour before going offline again.

AndrewS said:

If we have a future IEPS Type-054B, it's better to have a mix of generator sizes, so you can run an appropriate number of them at the most efficient range. In addition, you would still want at least 4 engines for redundancy purposes.

So they could go for the following: 2*5MW plus 2*12MW (total 34MW)

For non-wartime cruising, they could probably run the 2 smaller diesels efficiently at 75-100% load and still get 17-20knots.

With 5MW diesel engines, I'm not sure whether it is worth implementing an energy storage system. Yes, at low loads, it would be less efficient, but fuel is pretty cheap, and it takes time/money/space to implement an energy storage system.

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I was seeing if there is a viable pathway for this "a single beast to do the job from 5% load at the port all the way up to 100% power in a dash" with the new variable "large-capacity ESS" creating a workaround for efficiency issues. Otherwise, the point is valid.

F=XX Corsair said:

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I was seeing if there is a viable pathway for this "a single beast to do the job from 5% load at the port all the way up to 100% power in a dash" with the new variable "large-capacity ESS" creating a workaround for efficiency issues. Otherwise, the point is valid.

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The low load scenarios are almost certainly in port where shore-supplied electricity is the lowest cost option?

And if an IEPS Frigate is underway, then they would always want 2 diesel generators operating at say 75% (17? Knots).

And in a wartime scenario, they would always want at least 2 diesels running, irrespective of the load

JMSDF confirms sighting of 054B heading through the miyako strait possibly for its first voyage beyond the FIC, likely to conduct training operations with Liaoning.